#region License

/* Copyright (c) 2006 Leslie Sanford
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy 
 * of this software and associated documentation files (the "Software"), to 
 * deal in the Software without restriction, including without limitation the 
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 
 * sell copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
 * THE SOFTWARE.
 */

#endregion

#region Contact

/*
 * Leslie Sanford
 * Email: jabberdabber@hotmail.com
 */

#endregion

using System;
using System.Collections;
using System.ComponentModel;
using System.Diagnostics;
using Sanford.Collections;

namespace Sanford.Threading
{
    partial class DelegateScheduler
    {
        private class Task : IComparable
        {
            // The number of times left to invoke the delegate associated with this Task.
            private int count;

            // The interval between delegate invocation.
            private int millisecondsTimeout;

            // The delegate to invoke.
            private Delegate method;

            // The arguments to pass to the delegate when it is invoked.
            private object[] args;

            // The time for the next timeout;
            private DateTime nextTimeout;

            // For locking.
            private readonly object lockObject = new object();

            public Task(
                int count,
                int millisecondsTimeout,
                Delegate method,
                object[] args)
            {
                this.count = count;
                this.millisecondsTimeout = millisecondsTimeout;
                this.method = method;
                this.args = args;

                ResetNextTimeout();
            }

            public void ResetNextTimeout()
            {
                nextTimeout = DateTime.Now.AddMilliseconds(millisecondsTimeout);
            }

            public object Invoke(DateTime signalTime)
            {
                Debug.Assert(count == Infinite || count > 0);

                object returnValue = method.DynamicInvoke(args);

                if(count == Infinite)
                {
                    nextTimeout = nextTimeout.AddMilliseconds(millisecondsTimeout);
                }
                else
                {
                    count--;

                    if(count > 0)
                    {
                        nextTimeout = nextTimeout.AddMilliseconds(millisecondsTimeout);
                    }
                }

                return returnValue;
            }

            public object[] GetArgs()
            {
                return args;
            }

            public DateTime NextTimeout
            {
                get
                {
                    return nextTimeout;
                }
            }

            public int Count
            {
                get
                {
                    return count;
                }
            }

            public Delegate Method
            {
                get
                {
                    return method;
                }
            }

            public int MillisecondsTimeout
            {
                get
                {
                    return millisecondsTimeout;
                }
            }

            #region IComparable Members

            public int CompareTo(object obj)
            {
                Task t = obj as Task;

                if(t == null)
                {
                    throw new ArgumentException("obj is not the same type as this instance.");
                }

                return -nextTimeout.CompareTo(t.nextTimeout);
            }

            #endregion
        }
    }
}
